In my personal preferential order
1) Anything AAMC related. Both new exam material and old exam material(particularly AAMC 7-11) apply here. Any AAMC material is the best CARs practice you'll get period and alot of their Bio passages are still very applicable and great practice.
2) EK FL's: These were really well done.
3) BR FL's: The old ones got very good reviews and from what I've seen of the new ones they are quite good as well. The CARS is pretty bad, but you know that going in with BR. The psych/soc is meh but the science practice is so good it's worth doing and spending alot of time on.
4) Next Step: There psych/soc is good in particular. Very solid in general. I just an always going to be somewhat wary of recommending NS given some of the blatant issues they have(ie they have been caught blatantly copying a passage from the AAMC and putting it in their practice test).
All in all, all of these are worth doing. If you do all the AAMC stuff and say exams 7-11 as well(which I think are good practice and do all the verbals from all the exams from 3-9 R to 10 and 11), the EK, BR and NS FL's, you'll give yourself over a dozen FL's to work through. Not bad at all and the AAMC is releasing another FL in the fall which will be very clutch.
Additional practice can be found if you need it through Khan Academy passages( all in all there are over 200 of them), BR passages(there probably over 200 of them across all their science books), TPRH hyperlearning and supplement books(the verbal has about 100 passages through this and science around 200 passages), EK 101 verbal passages and some EK books as well( the CARS book had 20 or so very good passages, same with psych and bio). Add it all up and you probably have over 1000 passages to work with here from all of this and all of it is reasonably good prep for the actual MCAT.